Juvenile Salmon Ecology in Tidal Freshwater Wetlands of the Lower Columbia River Estuary: Synthesis of the Ecosystem Monitoring Program, 2005–2010

The Lower Columbia Estuary Partnership’s (Estuary Partnership’s) Ecosystem Monitoring Program (EMP) is an integrated status and trends program for the Lower Columbia River and Estuary (LCRE). The program is designed to track trends in the overall condition of the LCRE to reduce uncertainties, provide a suite of reference sites for use as end points in the region’s habitat restoration actions, and place findings from the program into context with the larger ecosystem. When the EMP was created in 2004, most previous research in the LCRE had occurred in the lower estuary, closest to the river mouth in Reaches A and B. There was a considerable lack of research and monitoring within the tidal freshwater section of the LCRE, resulting in little basic understanding of habitats, fish use and food web dynamics in this region. The EMP and partners developed a list of questions, and a subsequent monitoring design, directed at gaining a better understanding of how estuarine resources occur and interact in the LCRE. Specific questions are defined in each section of this report. Based on the knowledge gaps identified in the LCRE and the Estuary Partnership’s and the regional partner’s goals, the EMP goals for the 2005–2010 monitoring design were to:

Track the status and trends of ecosystem conditions to inform decisions for the purpose of conserving and restoring the LCRE through:

1. A comprehensive assessment of status (spatial variation) and trends (temporal variation) of habitat, fish, food web, and abiotic conditions in the lower river, focusing on relatively undisturbed shallow-water and vegetated habitats used extensively by juvenile salmonids for rearing and refugia;
2. A coordinated effort to gather baseline data about estuarine resources (Johnson et al. 2004);
3. A determination of the variety of salmon life histories currently expressed in the estuary and habitats that support them (from Bottomet al. 2005); and
4. A better understanding of salmon habitat associations to improve predictions of habitat opportunity in order to improve restoration strategies (from Bottom et al. 2005).
This report presents the results of all ecosystem monitoring data collected from 2005-2010. A subsequent report, released in 2015, focused on two main components of the EMP: variability in the status and trends data for the habitat structure, habitat hydrology, fish and fish prey components collected between 2005 and 2013 and a synthesis of food web dynamics in the LCRE collected between 2011 to 2013.  That report is available at http://www.estuarypartnership.org/resource/juvenile-salmon-ecology-tidal-freshwater-wetlands-lower-columbia-river-and-estuary
Sagar, J.P., A. B. Borde, L.L. Johnson, C. A. Corbett, J. L. Morace, K. H. Macneale, W.B. Temple , J. Mason, R.M Kaufmann, V.I. Cullinan, S. A. Zimmerman, R. M. Thom, C.L. Wright, P.M. Chittaro, O. P. Olson, S. Y. Sol, D. J. Teel, G. M. Ylitalo, , N.D. Ja